Fig. 3

Substrate and cofactor interactions within SmBdh molecule. a Omit Fo-Fc electron density map (calculated after NAD ⁺ and acetoin molecules removed from the model) shown at 3σ level for the NAD⁺ and acetoin molecules found in the ‘closed’ conformation of the WT SmBdh. b Omit Fo-Fc electron density map (calculated after ADP molecule was removed from the model) shown at 3σ level for the ADP molecule found in the ‘closed’ conformation of the WT SmBdh. c NAD ⁺ interactions with the ‘closed’ conformation of the WT SmBdh